Notes:

Data measure usual hourly earnings of wage and salary workers. Wage and salary workers are workers who receive wages, salaries, commissions, tips, payment in kind, or piece rates. The group includes employees in both the private and public sectors but, for the purposes of the earnings series, it excludes all self-employed persons, both those with incorporated businesses and those with unincorporated businesses. For more information see http://www.bls.gov/cps/earnings.htm

The series comes from the 'Current Population Survey (Household Survey)'